How to read varistor model _ commonly used varistor models

Varistor main parameters

1. Residual voltage: The highest peak voltage appearing at both ends of a varistor when it passes a large current of a specified waveform.
2. Flow capacity: The maximum current amplitude that can be passed by the varistor reference voltage after the specified waveform current is applied to the varistor according to the specified time interval and frequency.
3. Leakage current: The current flowing through the varistor under the action of the reference voltage.
4. Rated working voltage: The effective value of the power frequency voltage that is continuously applied to both ends of the varistor for a long time. The varistor absorbs the transient over-voltage energy and its temperature rises. Under this voltage, it can be cooled normally without heat damage.

Varistor advantages

Wide range of variable resistor voltages: 18V-1800V

Multiple surge withstand: standard, high surge, ultra high surge

High current handling and energy absorption

Monomer flow rate can reach 70KA or higher

Fast response time

Low leakage current

Multiple lead forms: straight, bent and other special lead types

A variety of packaging formats: bulk, package, roll packaging

Shortcomings of varistors

(1) Parasitic capacitance The large varistor has a large parasitic capacitance, and is generally in the range of several hundred to several thousand picofarads. In high-frequency signal systems, high-frequency signal transmission distortion is caused, which causes the system to operate normally.

(2) The existence of leakage current The leakage current index of the varistor is related to the normal operation of the protected electronic system and to the aging and service life of the varistor itself.

Damaged form of varistor: When the varistor exceeds its rated capacity when suppressing transient overvoltage, the varistor will be damaged by overheating, mainly as short circuit and open circuit.

How to read varistor model

The first part is denoted by the letter “M” and is mainly referred to as a sensitive resistor.

The second part uses the letter “Y” to indicate that the sensitive resistor is a varistor.

The third part uses letters to characterize the use of the varistor.

The fourth part uses numbers to indicate serial numbers, and some are also marked with nominal voltage, current capacity or resistor body diameter, voltage error, nominal voltage, etc. after the serial number.

E.g:
MYL1-1 (voltage sensitive resistor for lightning protection)

MY31-270/3 (270V/3kA ordinary varistor)

M – sensitive resistor

Y——varistor

L – lightning protection

31 – serial number

1-1 – serial number

270 – nominal voltage is 270V

3——The flow capacity is 3kA

Click here to learn more information about Varistor.